Fix local_sqrt_sqr rewrite logic bug

[WHOIM1205]

Fix swapped conditions in local_sqrt_sqr rewrite

The rewrite rule local_sqrt_sqr had the conditions for sqrt(sqr(x))
and sqr(sqrt(x)) reversed. Since prev_op represents the inner
operation and node_op the outer operation, the isinstance checks
were matching the wrong patterns.

Because of this, sqrt(sqr(x)) was rewritten to
switch(x >= 0, x, nan) instead of abs(x), which caused negative
inputs to return NaN. This silently breaks the mathematical identity
sqrt(x^2) = |x| and produces incorrect gradients.

This PR swaps the two isinstance checks so the rewrites match the
correct patterns:

• sqrt(sqr(x)) -> abs(x)
• sqr(sqrt(x)) -> switch(x >= 0, x, nan)

Tests were also updated to reflect the correct behavior and now include
numerical checks with negative inputs.

[WHOIM1205]

pre-commit.ci autofix

[WHOIM1205]

heyy @ricardoV94 is there anything i can improve in this pr

[ricardoV94]

Rebased and removed a redundant test.

Thanks for the bugfix